1. Technical Field
The subject matter herein relates generally to pick and place heads. More particularly, the present disclosure relates to the creation of a vacuum and air kiss on a pick and place machine as used in electronics assembly of printed circuit boards and other substrates.
2. Related Art
There are several different ways in which a vacuum and an air kiss is created for state of the art current electronics assembly machines. In a first method, a centralized vacuum pump is placed in the base of the electronics assembly machine. This centralized vacuum pump is configured to create a vacuum, that then and is connected through flexible hoses to multiple placement heads. The placement heads can either be stationary and positionable over a moving printed circuit board or substrate, or the placements heads may be mobile. The mobile placement heads may be configured to move in X- and Y-directions over a stationary printed circuit board. On each placement head this vacuum pump is consequently connected to multiple spindle assemblies, which can move in Z-direction and rotate around a vertical axis to enable the nozzle at the tip of the spindle assembly to pick an electronic component from a feeder and hold the component until the component is placed on the printed circuit board. To be able to place the part quickly, the nozzle, the spindle assembly and the placement head are also connected to a flexible hose that is connected to a factory compressed air system, or to a compressor in the base of the electronics assembly machine.
A variant on the above described system is to only bring the hose with the compressed air to the placement head, where subsequently a vacuum is created by the compressed air with the use of one or more venturis. In this case there is only one flexible hose that needs to be connected to the placement head.
In the case of a central vacuum pump, the pump needs to be able to maintain a vacuum when multiple spindles are open to the atmosphere, even when the spindle has failed to pick a component, or has picked up a component that would only partially close the flow of air through the nozzle. For this reason, a vacuum pump that provides a vacuum to multiple heads with each multiple spindles needs to be significantly over-engineered to provide for the situation where components are not properly picked up and the system experiences a resulting leakage of air from one or more of the nozzles.
Moreover, the disadvantage of using venturis to create a vacuum on the placement head is that a significant amount of air is used while creating the vacuum. This creates the demand for a large compressor, which in turn requires electricity and maintenance to provide this the compressed air. In order to reduce energy consumption and cost, there is currently a focused effort to minimize the consumption of compressed air in electronics assembly plants.
Another disadvantage of state of the art systems is the need to connect one or more flexible hoses to a fast moving placement head.
Thus, an assembly machine, system and method of use thereof that can be customizable and incrementally expanded that does not require predetermined feeder system positioning would be well received in the art.